Manufacturing processes for an electric motor include a process of winding wire on a bobbin, where various ingenuities have been implemented. When a wire with a rounded cross section is wound on a cylindrical surface of a round bobbin, for example, the diameter increases as the number of windings progresses, which increases the speed with a constant acceleration. According to JP7-106178A, a wire tension device is provided to respond to the speed change. According to 2005-235966A, when winding a wire having a rounded cross section on a square column surface of a rectangular bobbin, winding of the wire is controlled in response to a rotational position of the rectangular bobbin.
With constructions of known devices and methods where a wire with a rounded cross section is wound on a bobbin, there is a drawback that the wire is not wound with sufficiently high density.
A need thus exists for a wire winding apparatus, a method for winding a wire and a wire wound bobbin, which are not susceptible to the drawback mentioned above.